In this exercise you will:
The data in the table are the number of embryogenic anthers of the plant species Datura innoxia produced when numbers of anthers were produced under several different conditions. There is one qualitative factor, storage under special conditions or storage under standard conditions, and one quantitative factor, the centrifuging force (40, 150, 350). In the data given below y is the number of plants which did produce anthers and n is the total number tested at each combination of storage and force.
| Storage | Force | ||||
|---|---|---|---|---|---|
| 40 | 150 | 350 | |||
| Standard | y | 55 | 52 | 57 | |
| n | 102 | 99 | 108 | ||
| Special | y | 55 | 50 | 50 | |
| n | 76 | 81 | 90 |
Fit a logistic model to these data. Consider whether there is an interaction between storage and centrifuging force and whether the effect of force is linear on a logistic scale. Write a report on the analysis for the benefit of a biologist, explaining what the coefficients mean with the logit link.
You should compare your work with the solutions for this workshop.